Large diameter double twist spindles employed in the textile industry



Feb. 10, 1970 M,'R 1'T| LARGE DIAMETER DOUBLE .TWIST SPINDLES EMPLOYEDIN THE TEXTILE INDUSTRY Filed Aug. 26, 1968 fivarruu aal Sean-coATTORNEYS United States Patent 3,494,119 LARGE DIAMETER DOUBLE TWISTSPINDLES EMPLOYED IN THE TEXTILE INDUSTRY Michele Ratti, Luino, Varese,Italy Filed Aug. 26, 1968, Ser'. No. 767,881 Claims priority,application Italy, Aug. 28, 1967,

19,870/67 Int. Cl. D01h 1/10, 7/86 US. Cl. 57-58-84 2 Claims ABSTRACT OFTHE DISCLOSURE It is well known that when, on large diameter doubletwist spindles, the unwinding yarn accidentally breaks, it easily andoften occurs that, because of its high rotational speed and thecentrifugal force acting upon its broken end, the yarn keeps unwindingfrom the bobbin placed on the spindle.

A main object of the present invention is to eliminate this drawback.

The improvement to be described and claimed hereinafter is characterizedin that the rotating base of the spindle has two annular grooves ofdilferent diameters, each provided with a yarn guide element; the yarn,axially passing through the spindle from the upper to the lower endthereof, being made to pass in a substantially radial direction throughthe yarn guide element of the small diameter groove and successively ina direction substantially parallel to the spindle axis through the yarnguide element of the larger diameter groove; the broken yarn, as aconsequence of the air resistance encountered in the section between thetwo grooves, being made to partially wind up in the small diametergroove so that the unwinding process comes to an end.

The accompanying drawing shows by way of example only a preferrednon-limitative embodiment of the improvement according to the presentinvention.

FIG. 1 is an axially sectioned view of an improved spindle according tothe present invention;

FIG. 2 is a cross sectional view of the spindle taken along the plane2-2 in FIG. 1.

According to the present invention, the rotating base of the spindle isprovided with two annular grooves: a small diameter groove 5 placedbelow a larger diameter groove 1. Each of said grooves is provided witha yarn guide element. Groove 5 has a yarn guide element 6 so placedtherein as to direct the yarn in a substantially radial direction whilegroove 1 has its yarn guide element 4 so placed as to direct the yarn ina direction which is substantially parallel to the spindle axis.

Operation takes place in the following manner: the yarn 3 unwinding fromthe bobbin 7, axially passing therethrough from the upper to the lowerpart thereof and coming out from the axial yarn guide element 8, isguided in a substantially radial direction through the yarn 3,494,119Patented Feb. 10, 1970 guide element 6 of the small diameter groove 5from which it is made to pass in a direction substantially parallcl tothe spindle axis through the yarn guide member 4 of the large diametergroove 1 so that the formation of the so called ballon may start in theregion 3 external to the spindle.

Should the yarn break or get torn, the yarn section 3" comprised betweenthe yarn guide element 6 and the yarn guide element 4 (FIG. 2) byencountering a considerable air resistance as a consequence of the highrotational spindle speed, forms a kind of a loop as indicated with dashline in FIG. 2 and finally is wound up in the small diameter groove 5whereby the unwinding process comes to an end.

Without provision of the small diameter groove 5 the yarn coming outfrom the yarn guide element 4 would keep on unwinding from the bobbin,thereby not only giving rise to a considerable loss but, above all,interfering with the good development of the work.

Obviously the annular grooves may be placed in any part of the rotatingbase or they may consist of separate annular elements applied to therotating base. They may also be of any suitable shape without thereforedeparting from the spirit of the present invention.

What is claimed is:

1. An improvement to large diameter double twist spindles adapted toprevent the yarn, when it breaks, from keeping unwinding from the bobbinmounted on the spindle as a consequence of the centrifugal force actingthereupon, said improvement comprising a rotating hollow spindle, saidspindle having a base, two annular grooves of different diameters onsaid base, a yarn guide element on each of said diameters, the yarnafter passing through said hollow spindle from the upper to the lowerend thereof being led in a substantially radial direction through saidyarn guide element of the one of said grooves having the small diameterand successively in a direction substantially parallel to the axis ofsaid spindle through said yarn guide element of the other of saidgrooves having the larger diameter, said broken yarn in consequence ofthe air resistance encountered in the section between said two groovesbeing induced to partially wind up in said small diameter groove so thatsaid unwinding action comes to a stop.

2. The improvement as claimed in claim 1, said large diameter groovebeing located at said base of said rotating spindle corresponding to thestarting point for the ballon and said smaller diameter groove beingadjacent to said large diameter groove immediately below the latter.

References Cited UNITED STATES PATENTS 2,625,786 1/1953 Klein. 2,715,8118/1955 Kellogg 57--58.84 2,718,363 9/1955 Roberts.

FOREIGN PATENTS 982,865 2/ 1965 Great Britain.

JOHN PETRAKES, Primary Examiner US. Cl. X.R.

